1988 Century stereo installation problem

I'm trying to install a JVC head unit I used to have in my old Corolla in my brothers 88 Buick Century he just got as his first car. However, after getting the dash kit and trying to fit it in, im pretty sure I'm missing the DIN cage to mount to the dash kit. I'm thinking when i junked the Corolla, I took out the stereo but forgot the cage. Is there anything I can do/try/buy a new cage without having to buy a new head unit?

you can check e-bay or JVC themselves if the unit isn't too old.

I got the DIN cage, Best Buy gave me one they had lying around for free. I know the metal tabs have to be bent to lock it into the radio housing kit, but what attaches the headunit to the din cage? Won't the headunit just be able to slide out?

There are tabs that lock them together.